Hmm, somebody's being over-zealous. In the latest issue of the CWW email newsletter, Paul says to send an email with your name, mailing address and email address to firstname.lastname@example.org and you'll be set up to receive digital copies of the magazine free (if you're already a subscriber.
However, if you do so (as I did), your email will bounce. It gets flagged as spam.
Delivery to the following recipient failed permanently:
Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the recipient domain. We recommend contacting the other email provider for further information about the cause of this error. The error that the other server returned was: 550 550 5.7.1 Message rejected as spam by Content Filtering. (state 18).
Somebody didn't check things out ahead of time.